ChemDiv’s PLpro library contains 6,442 compounds.
COVID-19 disease is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 is classified as a betacoronavirus. As a betacoronavirus, SARS-CoV-2 encodes for a papain-like protease (PLpro) that is likely responsible for cleavage of the coronavirus viral polypeptide.
PLpro is an attractive antiviral drug target because it is essential for coronaviral replication. The PLpro is also responsible for the suppression of host innate immune responses through the reversal of post-translational modification of proteins by ubiquitin and interferon-stimulated gene product 15 (ISG15) Therefore, targeting PLpro with antiviral drugs may have an advantage in not only inhibiting viral replication but also inhibiting the dysregulation of signaling cascades in infected cells that may lead to cell death in surrounding, uninfected cells. Analyses of the structural differences the surrounding the active site BL2 loop of PLpro indicated that the plasticity of this loop and the amino acid side chains within this loop have a profound influence on the design of inhibitors against SARS-CoV PLpro and other coronavirus PLpro enzymes. [1,2]
 B. T. Freitas et al., “Characterization and Noncovalent Inhibition of the Deubiquitinase and deISGylase Activity of SARS-CoV-2 Papain-Like Protease,” ACS Infect. Dis., Jun. 2020, doi: 10.1021/acsinfecdis.0c00168.
 Y. M. Báez-Santos, S. E. St. John, and A. D. Mesecar, “The SARS-coronavirus papain-like protease: Structure, function and inhibition by designed antiviral compounds,” Antiviral Res., vol. 115, pp. 21–38, 2015, doi: 10.1016/j.antiviral.2014.12.015.